Field of the Invention
The present invention relates to signal processing, and in particular to a signal calibration circuit and a signal calibration method.
Description of the Related Art
SPDIF is the abbreviation for the Sony/Philips digital interface format. In terms of transmission, SPDIF is divided into two parts, SPDIF OUT and SPDIF IN. SPDIF OUT are supported by most sound card chipsets. However, it should be noticed that not every product is provided with a digital interface. The number of sound card chipsets support SPDIF IN (for example: EMU10K1, YMF-744, FM801-AU, CMI8738, and the like) is smaller than the number of sound card chipsets support SPDIF OUT. A typical application of SPDIF IN in a sound card chipset is CD Sony/Philips digital interface (SPDIF), but not every sound card chipset supporting SPDIF IN is equipped with such an interface.
However, when a audio signal is converted into a digital signal from an analog signal, an offset might occur for the pulses in the audio signal, this would affect the accuracy of the audio signal, and cause the distortion of the audio signal.